1. Field of the Invention
The invention relates to a device for transmitting optical signals between units that are rotatable relative to each other, also known as a rotary coupling or rotary joint. With this, preferably a plurality of optical signals can be transmitted simultaneously along a plurality of channels.
2. Description of the Prior Art
Various transmission systems are known for transmission of optical signals between units that are rotatable relative to each other.
An optical rotary joint for a plurality of channels, comprising a Dove prism, is disclosed in U.S. Pat. No. 5,568,578. An arrangement having a plurality of GRIN lenses is provided for coupling-in or coupling-out light. The Dove prism must be rotated by a precise gear mechanism at exactly one-half of the angular velocity between the two units that are rotatable relative to each other.